U.S. patent application number 15/318872 was filed with the patent office on 2017-09-07 for stator.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. The applicant listed for this patent is AISIN SEIKI KABUSHIKI KAISHA. Invention is credited to Naoki KAMIYA, Akihiro ONO.
Application Number | 20170257001 15/318872 |
Document ID | / |
Family ID | 55746492 |
Filed Date | 2017-09-07 |
United States Patent
Application |
20170257001 |
Kind Code |
A1 |
KAMIYA; Naoki ; et
al. |
September 7, 2017 |
STATOR
Abstract
A stator having good electric characteristics is reasonably
configured. The stator includes a stator core including an annular
core portion centered around a rotational axis of a rotor and a
plurality of teeth portions protruding radially from the core
portion, a core wire wound around the teeth portions, a resin plate
to be superposed on the stator core along the rotational axis, the
resin plate defining a hole therethrough along the rotational axis,
into which hole an end portion of the coil wire is inserted, and a
resin portion in which the stator core, the coil wire and the plate
are embedded. The end of the coil wire is directly connected to a
bus bar for electric power supply or grounding, with the end of the
coil wire being exposed from the resin portion.
Inventors: |
KAMIYA; Naoki; (Anjo-shi,
Aichi, JP) ; ONO; Akihiro; (Chita-gun, Aichi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN SEIKI KABUSHIKI KAISHA |
Kariya-shi, Aichi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi, Aichi
JP
|
Family ID: |
55746492 |
Appl. No.: |
15/318872 |
Filed: |
September 18, 2015 |
PCT Filed: |
September 18, 2015 |
PCT NO: |
PCT/JP2015/076643 |
371 Date: |
December 14, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K 3/44 20130101; H02K
3/28 20130101; H02K 3/522 20130101; H02K 3/12 20130101; H02K 3/30
20130101 |
International
Class: |
H02K 3/28 20060101
H02K003/28; H02K 3/30 20060101 H02K003/30; H02K 3/12 20060101
H02K003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2014 |
JP |
2014-209873 |
Claims
1. A stator comprising: a stator core including an annular core
portion centered around a rotational axis of a rotor and a
plurality of teeth portions protruding radially from the core
portion; a core wire wound around the teeth portions; a resin plate
to be superposed on the stator core along the rotational axis, the
resin plate defining a hole therethrough along the rotational axis,
into which hole an end portion of the coil wire is inserted; and a
resin portion in which the stator core, the coil wire and the plate
are embedded; wherein the end of the coil wire is directly
connected to a bus bar for electric power supply or grounding, with
the end of the coil wire being exposed from the resin portion.
2. The stator according to claim 1, wherein: the plate includes a
first plate and a second plate placed on the first plate; the first
plate defines a first groove portion configured to be connected to
the hole of the first plate and to accommodate the coil wire; and
the hole of the second plate is communicated to the first groove
portion.
3. The stator according to claim 2, wherein the second plate
defines a second groove portion which is formed in opposition to
the first groove portion and configured to accommodate the coil
wire.
4. The stator according to claim 2, wherein the second plate
includes a protruding portion which is inserted into the first
groove portion, the protruding portion defining a second groove
portion for accommodating the coil wire.
Description
TECHNICAL FIELD
[0001] The present invention relates to a stator of a rotating
electrical machine, more particularly, to an end treatment of a
coil wire wound around a stator core.
BACKGROUND ART
[0002] As a conventional stator, there is known a stator including
a stator core and a coil wire wound around the stator core, with an
end of the coil wire being connected via a terminal member to a bus
bar for electric power supply or grounding (see e.g. Patent
Document 1).
[0003] In the stator disclosed in Patent Document 1, the stator
core and the coil wire are insert-molded, with an end of the coil
wire being inserted in a hole of a mold. In this, the document
describes that in order to prevent leak of injected resin via a gap
formed between the mold hole and the end of the coil wire, a
predetermined sealing arrangement is provided on the side of the
mold (paragraph [0079]). Next, as the end of the coil wire is
brought into contact with the terminal member which is fixed to the
bus bar, electric connection is established between the bus bar and
the coil wire.
CITATION LIST
[0004] Patent Document 1: Japanese Unexamined Patent Application
Publication No. 2011-205875
SUMMARY OF INVENTION
Technical Problem
[0005] However, with the conventional stator, this requires an
operation of inserting into the mold hole, with adjustment of the
position of the end of the coil wire being effected concurrently.
Thus, the assembly is troublesome. Further, the sealing arrangement
provided in the mold may present an "obstacle", which makes the
insertion of the coil wire into the mold hole difficult. On the
other hand, if such sealing arrangement were omitted, injected
resin would leak to reach the position connected to the terminal
member of the coil wire, thus forming burr, which may eventually
inhibit or impair the electrical connection between the terminal
member and the coil wire.
[0006] Further, in the conventional stator, the coil wire and the
bus bar are connected via the terminal member, thus inviting
increase of the number of components and/or deterioration in the
electric characteristics due to increase of contact resistance
between these components.
[0007] Then, there is a need for reasonably configuring a stator
having good electric characteristics.
SOLUTION TO PROBLEM
[0008] According to a characterizing feature of a stator relating
to the present invention, the stator comprises: a stator core
including an annular core portion centered around a rotational axis
of a rotor and a plurality of teeth portions protruding radially
from the core portion; a core wire wound around the teeth portions;
a resin plate to be superposed on the stator core along the
rotational axis, the resin plate defining a hole therethrough along
the rotational axis, into which hole an end portion of the coil
wire is inserted; and a resin portion in which the stator core, the
coil wire and the plate are embedded; wherein the end of the coil
wire is directly connected to a bus bar for electric power supply
or grounding, with the end of the coil wire being exposed from the
resin portion.
[0009] As described above, when the stator core is to be set to the
mold, it is necessary to align the end of the core coil in position
with the hole of the mold, while correcting shape/posture of the
end of the coil wire, thus being troublesome. On the other hand,
with the inventive arrangement above, it is possible to hold the
end of the coil wire by inserting this end into the hole defined in
the plate that lies over the stator core and extends along the
rotational axis. As a result, when this end is to be inserted into
the hole of the mold, the shape/posture of the coil wire can be
stabilized. Therefore, the insertion of the coil wire into the mold
hole can proceed smoothly, thus improving manufacture
efficiency.
[0010] Further, with the above-described inventive arrangement, the
end of the coil wire is directly connected to the bus bar, with
this end being exposed from the resin portion. Thus, in comparison
with an arrangement of connecting the coil wire and the bus bar via
a terminal member, compactization is made possible with reduction
in the number of components corresponding to omission of the
terminal member. Moreover, as the arrangement eliminates a contact
portion between the terminal member and the coil wire and/or a
contact portion between the terminal member and the bus bar, it is
possible to improve the electric characteristics with reduction of
contact resistance.
[0011] In this way, by disposing the stator core, the coil and the
plate in this order along the rotational axis and accommodating an
end of the coil wire in the hole of plate extending along the
rotational axis, it has become possible to rationally configure a
stator having good electrical characteristics.
[0012] According to a further characterizing feature;
[0013] the plate includes a first plate and a second plate placed
on the first plate;
[0014] the first plate defines a first groove portion configured to
be connected to the hole of the first plate and to accommodate the
coil wire; and
[0015] the hole of the second plate is communicated to the first
groove portion.
[0016] With the above-described arrangement wherein the plate
comprises two members and the first groove portion of the first
plate is communicated to the respective holes of the first plate
and the second plate, it becomes possible to offset the hole of the
first plate and the hole of the second plate relative to each other
as seen in the direction of the rotational axis. Therefore, resin
entering the hole of the first plate will hardly reach the hole of
the second plate via the first groove portion. Namely, as the resin
exiting the hole of the first plate will encounter a drop of its
pressure at the first groove portion, so that discharge of the
resin from the hole of the second plate will hardly occur.
Eventually, leak of injected resin to the hole of the mold in which
the end portion of the coil wire is inserted will hardly occur,
either. Consequently, it is possible to solve the inconvenience of
formation of burr at the end of the coil wire, which would lead to
deterioration of electrical characteristics.
[0017] According to a further characterizing feature, the second
plate defines a second groove portion which is formed in opposition
to the first groove portion and configured to accommodate the coil
wire.
[0018] With the above-described arrangement of defining a second
groove portion in the second plate also, it is possible to dispose
the second plate on the first plate with fitting the coil wire
exposed from the first groove portion within the second groove
portion. Thus, attachment is facilitated.
[0019] According to a still further characterizing feature, the
second plate includes a protruding portion which is inserted into
the first groove portion, the protruding portion defining a second
groove portion for accommodating the coil wire.
[0020] With the above arrangement of forming a protruding portion
in the second plate and inserting this protruding portion in the
first groove portion of the first plate, position-fixing of the
second plate relative to the first plate can be carried out easily.
Moreover, since the second groove portion in which the coil wire is
accommodated is formed in the protruding portion constituting a
position fixed portion, there is no need to provide a position
fixing portion separately.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a section view of a water pump,
[0022] FIG. 2 is a section view of a stator core,
[0023] FIG. 3 is an exploded perspective view of the stator core
and a plate,
[0024] FIG. 4 is a section showing a molded example of the
stator,
[0025] FIG. 5 is a partial perspective view of the stator,
[0026] FIG. 6 is a partial perspective view of a plate according to
Further Embodiment 1,
[0027] FIG. 7 is a section view showing a molded example of stator
according to Further Embodiment 1,
[0028] FIG. 8 is a partial perspective view of a plate according to
Further Embodiment 2, and
[0029] FIG. 9 is a partial perspective view of a plate according to
Further Embodiment 3.
DESCRIPTION OF EMBODIMENTS
[0030] Next, a stator relating to this embodiment will be explained
with reference to the drawings. In this embodiment, as an example
of stator, there will be explained a stator 4 of an electric motor
M used in a water pump P for a vehicle configured to circulate
cooling water. However, it should be noted that this invention is
not limited to the following embodiment, but various modifications
are possible in a range not departing from the essential spirit
thereof.
[0031] As shown in FIG. 1, the water pump P includes a resin casing
1, a support shaft 2 fixed to the casing 1, a cylindrical rotor 3
rotatable as being externally fitted on the support shaft 2, a
cylindrical stator 4 disposed on the outer side of the rotor 3, and
an impeller 5 fixed to one end of the rotor 3. As this impeller 5
is accommodated in a housing 6, there is constituted the water pump
P configured to circulate cooling water to an inverter or
circulating cooling water between an engine and a radiator.
[0032] The electric motor M for use in this water pump P comprises
a three-phase brushless motor having the rotor 3 rotatable about a
rotational axis X and the stator 4 for generating magnetic flux
relative to the rotor 3. Incidentally, this electric motor M can be
caused to function as a generator by rotating the rotor 3.
[0033] The rotor 3 includes a rotor core 31 formed by superposing a
plurality of magnetic steel plates and a plurality of permanent
magnets 31a embedded in the rotor core 31. The rotor core 31 and
the permanent magnets 31a are insert-molded with resin and
integrated with each other. The permanent magnets 31a are comprised
of six magnetic poles, thus constituting the electric motor M
having 6 poles, three phases, 9 throttles.
[0034] Incidentally, the permanent magnets 31a are not limited to
six poles, but can be comprised of an even number of poles more
than 2 (two) poles.
[0035] As shown in FIG. 3, the stator 4 includes a cylindrical
stator core S, a resin insulator 44 encasing the stator core S, a
coil C wound around a outer face of the insulator 44, and a
cylindrical core case 7 holding the stator core S.
[0036] As shown in FIG. 2, the stator core S includes a core
portion 41 formed in an annular region centering about a rotational
axis X, a plurality of teeth portions 42 protruding from the core
portion 41 in a radially inner direction, and flange portions 43
disposed along a circumferential direction about the rotational
axis X at protruding ends of the plurality of teeth portions 42.
This stator core S comprises split cores formed by forming a core
member by laminating magnetic steel plates and then combing the
plurality of such core members in an annular form. These split
cores are held with their split faces being placed in contact with
each other and the core case 7 being fitted externally thereon.
[0037] The respective teeth portions 42 extend radially (radial
direction) around the rotational axis X and formed at 9 (nine)
positions spaced apart from each other equidistantly along the
circumferential direction. In the instant embodiment, the outer
circumferential face of the core portion 41 comprises a nonagonal
shape and the inner circumferential face of the core case 7 fitted
along the outer circumferential face of this core portion 41
comprises also a nonagonal shape. Incidentally, the outer
circumferential face of the core portion 41 and the inner
circumferential face of the core case 7 are not limited to such
polygonal shapes, but can be circular shape also, for instance.
[0038] As shown in FIG. 3, in the stator 4, with the resin
insulator 44 being externally fitted on the stator core S, a coil
wire 45 is wound around the teeth portion 42, thus forming a coil
C. Though will be detailed later herein, the stator 4 with the coil
C being wound is insert-molded with resin. The insulator 44 is
provided for insulation between the stator core S and the coil C
and covers at least the outer face of the teeth portion 42 and the
inner faces of the core portion 41 and the flange portion 43. Also,
in the coil wire 45, a resin such as polyurethane is coated on a
surface of a copper wire having a round cross sectional shape.
Incidentally, if appropriate insulation can be ensured between the
stator core S and the coil C, the coil wire 45 may be directly
wound around the teeth portion 42.
[0039] In the instant embodiment, as shown in FIG. 4, the stator 4
includes a resin portion 46 formed in the stator core S by
injecting resin via an inlet E opposite to ends 45A of the coil
wire 45 in the rotational axis X direction. A mold K for molding
this resin portion 46 defines hole portions Ka into which the ends
45A of the coil wire 45 are to be inserted. As the inserting
operation needs to be carried out with aligning the ends 45A of the
coil wire 45 in position with the hole portions Ka, the assembly is
troublesome.
[0040] Then, in the case of the stator 4 according to the instant
embodiment, as shown in FIG. 3, there is provided a resin plate 8
that defines holes 81 for allowing insertion of the ends 45A of the
coil wire 45 and that is to be superposed on the stator core S
along the rotational axis X, with the holes 81 being formed through
the plate 8 along the rotational axis X. This plate 8 is formed as
a polygonal integral shape or split shapes as seen in the
rotational axis X direction and is fixed in position as being
placed in abutment against the inner circumferential face of the
core case 7 and the outer circumferential face of the insulator 44
covering the flange portion 43. Incidentally, the manner of
position-fixing of the plate 8 is not particularly limited. For
instance, instead of the inner circumferential face of the core
case 7, the insulator 44 covering the core portion 41 may be caused
to protrude in the rotational axis X direction and the plate 8 may
be placed in abutment against the inner circumferential face of
this insulator 44. Further, the shape of the plate 8 is not
particularly limited, but can be set appropriately in accordance
with the shapes of the insulator 44 and the core case 7.
[0041] As described above, the plate 8 defines therethrough the
holes 81 along the rotational axis X for allowing insertion of the
ends 45A of the coil wire 45. Thus, as shown in FIG. 4, it is
possible to insert the ends 45A into the hole portions Ka of the
mold K smoothly, with maintaining the shape/posture of the ends 45A
of the coil wire 45 in a stable manner. Then, when resin is
injected via the inlet E, the stator core S, the coil wire 45 and
the plate 8 will be insert-molded as being embedded in the resin
portion 46.
[0042] As shown in FIG. 5, in the insert-molded stator 4, the ends
45A of the coil wire 45 are exposed from the resin portion 46 and
are directly connected to bus bars B for electric power supply or
grounding incorporated in a substrate (not shown). Incidentally,
the ends 45A of the coil wire 45 and the bus bars B will be
electrically connected to each other by effecting fusing (thermal
calking) or spot welding, etc.
[0043] Namely, the stator 4 according to the instant embodiment
omits any terminal member for establishing electric connection
between the coil wire 45 and the bus bar B.
[0044] On the other hand, such omission of terminal member results
in greater trouble in inserting the ends 45A of the coil wire 45
into the hole portions Ka of the mold K. However, by providing the
plate 8, the assembly can be facilitated. Moreover, since a contact
portion between a terminal member and the coil wire 45 and a
contact portion between the terminal member and the bus bar B are
eliminated, contact resistance can be reduced, thus improving the
electric characteristics.
[0045] Next, further embodiments will be explained. As basic
configurations thereof are identical to that of the foregoing
embodiment, only differences thereof will be explained with
reference to the drawings. Incidentally, for readiness of
understanding of drawing illustrations, in the following
explanation, the same parts names and marks as those employed in
the foregoing embodiment will be used in the following
explanation.
Further Embodiment 1
[0046] As shown in FIG. 6, a plate 8 in this embodiment is
comprised of two components, i.e. a first plate 8a and a second
plate 8b which is placed on the first plate 8a. The first plate 8a
includes holes 81a into which the ends 45A of the coil wire 45 are
inserted and first groove portions 82a connected to the holes 81a
and accommodating the coil wire 45. Further, the second plate 8b
includes holes 81b into which the ends 45A of the coil wire 45 are
inserted and which are communicated to the first groove portions
82a. Namely, the holes 81a of the first plate 8a and the holes 81b
of the second plate 8b are offset relative to each other as seen in
the rotational axis X direction.
[0047] As shown in FIG. 7, a portion of an amount of resin
introduced via the inlet E of the stator core S disposed opposite
to the ends 45A of the coil wire 45 in the rotational axis X
direction will flow into the holes 81a of the first plate 8a. This
resin flown out of the holes 81a will then flow into the first
groove portions 82a of the first plate 8a. In this, the flowing
direction of the resin changes from the direction along the
rotational axis X to a direction perpendicular to the rotational
axis X. Thus, the resin will encounter pressure drop, which makes
it difficult for the resin to reach the holes 81b of the second
plate 8b.
[0048] As a result, leakage or discharge of injected resin from the
holes 81b of the second plate 8b is prevented. Thus, the
arrangement eliminates inconvenience of leaking of resin into the
hole portions Ka of the mold K, generating burrs at the ends 45A of
the coil wire 45. Therefore, even if the ends 45A of the coil wire
45 exposed from the resin portion 46 of the stator 4 are directly
connected to the bus bars B, no deterioration will occur in the
electric characteristics.
[0049] Incidentally, as the ends 45A of the coil wire 45 are drawn
out of the offset holes 81b of the second plate 8b, the layout of
the first groove portions 82a can be determined according to the
positions for connection to the bus bars B. Namely, the arrangement
of constituting the plate 8 of two parts provides greeter degree of
freedom in setting of drawing out positons of the ends 45A of the
coil wire 45.
Further Embodiment 2
[0050] This embodiment differs from Further Embodiment 1 in the
respect of the shape of the second plate 8b. As shown in FIG. 8,
the second plate 8b defines second groove portions 82b which are in
opposition to the first groove portions 82a of the first plate 8a
and configured to accommodate the coil wire 45. Namely, the coil
wire 45 will be accommodated in the first groove portions 82a and
the second groove portions 82b as being sandwiched therebetween,
and the holes 81a of the first plate 8a and the holes 81b of the
second plate 8b are communicated to the first grove portions 82a
and the second groove portions 82b.
[0051] With the above-described arrangement, in addition to the
advantageous function/effect of Further Embodiment 1, as the
positioning of the second plate 8b relative to the first plate 8a
is effected with fitting the second groove portion 82b to the coil
wire 45 exposed from the first groove portions 82a, attachment is
facilitated.
Further Embodiment 3
[0052] This embodiment differs from Further Embodiments 1 and 2 in
the respect of the shape of the second plate 8b. As shown in FIG.
9, the second plate 8b includes protruding portions 83 which are to
be inserted into the first groove portions 82a; the protruding
portions 83 defining second groove portions 83a for accommodating
the coil wire 45. More particularly, in the protruding portion 83,
there are formed a pair of lateral walls 83b for sandwiching the
coil wire 45, and between these lateral walls 83b, the second
groove portion 83a is provided.
[0053] With the above-described embodiment, in addition to the
advantageous function/effect of Further Embodiments 1 and 2, only
by inserting the protruding portion 83 having the first groove
portion 82a into the first groove portion 82a acting as an
accommodation space for the coil wire 45, position fixing of the
two members can be completed. Therefore, there is no need to
provide the first plate 8a or the second plate 8b with e.g. a
position fixing portion separately.
Other Embodiments
[0054] (1) In the foregoing embodiments, the plate 8 is provided in
the form of an integrated annular shape or a half-annular shape.
However, the plate 8 may be formed independently for each split
stator core S. In this case, the size of the plate 8 will be
determined in accordance with an amount of withdrawal extension of
the ends 45A of the coil wire 45. Thus, material for forming the
plate 8 can be saved.
[0055] (2) The stator core S in the foregoing embodiment was
described as a split core. Instead, this can be an integral core
integrating the core portions 41. In this case, the core case 7 can
be omitted and the insulator 44 encasing the core portion 41 can be
formed to protrude in the rotational axis X direction, and the
plate 8 can be placed in abutment against the inner circumferential
face of this insulator 44.
[0056] (3) In the foregoing embodiment, the electric motor M is of
the inner rotor type in which the rotor 3 is disposed on the inner
side of the stator 4. Alternatively, it may be of an outer rotor
type in which the rotor 3 is disposed on the outer side of the
stator 4. In the case of such outer rotor type, the stator 4 will
include an annular core portion 41 centered around the rotational
axis X and a plurality of teeth portions 42 protruding radially
outwards from the core portion 41. In this outer rotor type
electric motor M too, the above-described function/effect can be
expected to be obtained by providing the plate 8 to be placed on
the stator core S along the rotational axis X.
[0057] (4) The machine in which the electric motor M in the
foregoing embodiment is used is not limited to the water pump P for
circulating cooling water for an engine, but may be a pump for
circulating engine oil or even a machine for use in other
applications than a vehicle. Further, the driving mode of the
electric motor M is not limited to the three-phase brushless motor
generating alternating magnetic field. Instead a brush motor may be
employed.
INDUSTRIAL APPLICABILITY
[0058] The stator according to the present invention is applicable
to an electric motor for use in various machines such as a
vehicle-mounted water pump.
REFERENCE SIGNS LIST
[0059] 3: rotor [0060] 4: stator [0061] 41: core portion [0062] 42:
teeth portion [0063] 43: flange portion [0064] 45: coil wire [0065]
45A: end [0066] 46: resin portion [0067] 8: plate [0068] 81: hole
[0069] 8a: first plate [0070] 81a: hole [0071] 82a: first groove
portion [0072] 8b: second plate [0073] 81b: hole [0074] 82b: second
groove portion [0075] 83: protruding portion [0076] 83a: second
groove portion [0077] B: bus bar [0078] S: stator core [0079] X:
rotational axis
* * * * *